[J-u-boot.git] / drivers / video / pwm_backlight.c

/*
 * Copyright (c) 2016 Google, Inc
 * Written by Simon Glass <[email protected]>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <dm.h>
#include <backlight.h>
#include <pwm.h>
#include <asm/gpio.h>
#include <power/regulator.h>

DECLARE_GLOBAL_DATA_PTR;

struct pwm_backlight_priv {
	struct udevice *reg;
	struct gpio_desc enable;
	struct udevice *pwm;
	uint channel;
	uint period_ns;
	uint default_level;
	uint min_level;
	uint max_level;
};

static int pwm_backlight_enable(struct udevice *dev)
{
	struct pwm_backlight_priv *priv = dev_get_priv(dev);
	uint duty_cycle;
	int ret;

	debug("%s: Enable '%s', regulator '%s'\n", __func__, dev->name,
	      priv->reg->name);
	ret = regulator_set_enable(priv->reg, true);
	if (ret) {
		debug("%s: Cannot enable regulator for PWM '%s'\n", __func__,
		      dev->name);
		return ret;
	}
	mdelay(120);

	duty_cycle = priv->period_ns * (priv->default_level - priv->min_level) /
		(priv->max_level - priv->min_level + 1);
	ret = pwm_set_config(priv->pwm, priv->channel, priv->period_ns,
			     duty_cycle);
	if (ret)
		return ret;
	ret = pwm_set_enable(priv->pwm, priv->channel, true);
	if (ret)
		return ret;
	mdelay(10);
	dm_gpio_set_value(&priv->enable, 1);

	return 0;
}

static int pwm_backlight_ofdata_to_platdata(struct udevice *dev)
{
	struct pwm_backlight_priv *priv = dev_get_priv(dev);
	struct fdtdec_phandle_args args;
	const void *blob = gd->fdt_blob;
	int node = dev->of_offset;
	int index, ret, count, len;
	const u32 *cell;

	ret = uclass_get_device_by_phandle(UCLASS_REGULATOR, dev,
					   "power-supply", &priv->reg);
	if (ret) {
		debug("%s: Cannot get power supply: ret=%d\n", __func__, ret);
		return ret;
	}
	ret = gpio_request_by_name(dev, "enable-gpios", 0, &priv->enable,
				   GPIOD_IS_OUT);
	if (ret) {
		debug("%s: Warning: cannot get enable GPIO: ret=%d\n",
		      __func__, ret);
		if (ret != -ENOENT)
			return ret;
	}
	ret = fdtdec_parse_phandle_with_args(blob, node, "pwms", "#pwm-cells",
					     0, 0, &args);
	if (ret) {
		debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret);
		return ret;
	}

	ret = uclass_get_device_by_of_offset(UCLASS_PWM, args.node, &priv->pwm);
	if (ret) {
		debug("%s: Cannot get PWM: ret=%d\n", __func__, ret);
		return ret;
	}
	priv->channel = args.args[0];
	priv->period_ns = args.args[1];

	index = fdtdec_get_int(blob, node, "default-brightness-level", 255);
	cell = fdt_getprop(blob, node, "brightness-levels", &len);
	count = len / sizeof(u32);
	if (cell && count > index) {
		priv->default_level = fdt32_to_cpu(cell[index]);
		priv->max_level = fdt32_to_cpu(cell[count - 1]);
	} else {
		priv->default_level = index;
		priv->max_level = 255;
	}


	return 0;
}

static int pwm_backlight_probe(struct udevice *dev)
{
	return 0;
}

static const struct backlight_ops pwm_backlight_ops = {
	.enable	= pwm_backlight_enable,
};

static const struct udevice_id pwm_backlight_ids[] = {
	{ .compatible = "pwm-backlight" },
	{ }
};

U_BOOT_DRIVER(pwm_backlight) = {
	.name	= "pwm_backlight",
	.id	= UCLASS_PANEL_BACKLIGHT,
	.of_match = pwm_backlight_ids,
	.ops	= &pwm_backlight_ops,
	.ofdata_to_platdata	= pwm_backlight_ofdata_to_platdata,
	.probe		= pwm_backlight_probe,
	.priv_auto_alloc_size	= sizeof(struct pwm_backlight_priv),
};
Commit	Line	Data
65fba592 SG	1	/*
	2	* Copyright (c) 2016 Google, Inc
	3	* Written by Simon Glass <[email protected]>
	4	*
	5	* SPDX-License-Identifier: GPL-2.0+
	6	*/
	7
	8	#include <common.h>
	9	#include <dm.h>
	10	#include <backlight.h>
	11	#include <pwm.h>
	12	#include <asm/gpio.h>
	13	#include <power/regulator.h>
	14
	15	DECLARE_GLOBAL_DATA_PTR;
	16
	17	struct pwm_backlight_priv {
	18	struct udevice *reg;
	19	struct gpio_desc enable;
	20	struct udevice *pwm;
	21	uint channel;
	22	uint period_ns;
	23	uint default_level;
	24	uint min_level;
	25	uint max_level;
	26	};
	27
	28	static int pwm_backlight_enable(struct udevice *dev)
	29	{
	30	struct pwm_backlight_priv *priv = dev_get_priv(dev);
	31	uint duty_cycle;
	32	int ret;
	33
	34	debug("%s: Enable '%s', regulator '%s'\n", __func__, dev->name,
	35	priv->reg->name);
	36	ret = regulator_set_enable(priv->reg, true);
	37	if (ret) {
	38	debug("%s: Cannot enable regulator for PWM '%s'\n", __func__,
	39	dev->name);
	40	return ret;
	41	}
	42	mdelay(120);
	43
	44	duty_cycle = priv->period_ns * (priv->default_level - priv->min_level) /
	45	(priv->max_level - priv->min_level + 1);
	46	ret = pwm_set_config(priv->pwm, priv->channel, priv->period_ns,
	47	duty_cycle);
	48	if (ret)
	49	return ret;
	50	ret = pwm_set_enable(priv->pwm, priv->channel, true);
	51	if (ret)
	52	return ret;
	53	mdelay(10);
	54	dm_gpio_set_value(&priv->enable, 1);
	55
	56	return 0;
	57	}
	58
	59	static int pwm_backlight_ofdata_to_platdata(struct udevice *dev)
	60	{
	61	struct pwm_backlight_priv *priv = dev_get_priv(dev);
	62	struct fdtdec_phandle_args args;
	63	const void *blob = gd->fdt_blob;
	64	int node = dev->of_offset;
65	int index, ret, count, len;
66	const u32 *cell;
67
68	ret = uclass_get_device_by_phandle(UCLASS_REGULATOR, dev,
69	"power-supply", &priv->reg);
70	if (ret) {
71	debug("%s: Cannot get power supply: ret=%d\n", __func__, ret);
72	return ret;
73	}
74	ret = gpio_request_by_name(dev, "enable-gpios", 0, &priv->enable,
75	GPIOD_IS_OUT);
76	if (ret) {
77	debug("%s: Warning: cannot get enable GPIO: ret=%d\n",
78	__func__, ret);
79	if (ret != -ENOENT)
80	return ret;
81	}
82	ret = fdtdec_parse_phandle_with_args(blob, node, "pwms", "#pwm-cells",
83	0, 0, &args);
84	if (ret) {
85	debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret);
86	return ret;
87	}
88
89	ret = uclass_get_device_by_of_offset(UCLASS_PWM, args.node, &priv->pwm);
90	if (ret) {
91	debug("%s: Cannot get PWM: ret=%d\n", __func__, ret);
92	return ret;
93	}
94	priv->channel = args.args[0];
95	priv->period_ns = args.args[1];
96
97	index = fdtdec_get_int(blob, node, "default-brightness-level", 255);
98	cell = fdt_getprop(blob, node, "brightness-levels", &len);
99	count = len / sizeof(u32);
100	if (cell && count > index) {
101	priv->default_level = fdt32_to_cpu(cell[index]);
102	priv->max_level = fdt32_to_cpu(cell[count - 1]);
103	} else {
104	priv->default_level = index;
105	priv->max_level = 255;
106	}
107
108
109	return 0;
110	}
111
112	static int pwm_backlight_probe(struct udevice *dev)
113	{
114	return 0;
115	}
116
117	static const struct backlight_ops pwm_backlight_ops = {
118	.enable = pwm_backlight_enable,
119	};
120
121	static const struct udevice_id pwm_backlight_ids[] = {
122	{ .compatible = "pwm-backlight" },
123	{ }
124	};
125
126	U_BOOT_DRIVER(pwm_backlight) = {
127	.name = "pwm_backlight",
128	.id = UCLASS_PANEL_BACKLIGHT,
129	.of_match = pwm_backlight_ids,
130	.ops = &pwm_backlight_ops,
131	.ofdata_to_platdata = pwm_backlight_ofdata_to_platdata,
132	.probe = pwm_backlight_probe,
133	.priv_auto_alloc_size = sizeof(struct pwm_backlight_priv),
134	};